Previously, a technique has been known which restores blurring of a picked up image by performing divided exposures for a plurality of times using the same electronic camera, and positioning and composing the plurality of obtained images (refer to, for example, patent document 1 below). Pattern matching, block matching, or the like are known as a processing to detect such position discrepancy of multiple images.
The following patent document 2 is known as a technique of detecting position discrepancy of patterns between images which have been output from separate imaging sensors having different resolutions. This prior art technique first performs a global search between a high resolution image and low resolution images to find candidates of a coincide region. The technique then performs pixel interpolation on both images respectively, in the coincide region to find a region in which the patterns coincide in detail by comparison between interpolated pixels. With such a two-phase search processing, position discrepancy is detected between images having different resolutions.    Patent Document 1: Japanese Unexamined Patent Application Publication No. 2002-107787    Patent Document 2: WO 95/04329